Military tactical vehicles are exposed to collisions, rollovers, and resultant secondary impact effects of mine blast or improvised explosive devices (IED's). Therefore, tactical vehicles are often heavily armored on both the exterior and interior of the vehicle.
Materials used for occupant energy absorbing must have several characteristics in order to sufficiently protect occupants from suffering bodily injury and head trauma. They must be somewhat flexible in order to avoid causing injuries due to collisions between occupants and the energy absorbing panels themselves. They must be lightweight to avoid increasing the total vehicle weight and fuel requirements beyond an acceptable point. They must be easily produced in sufficient quantities so as not to increase cost beyond acceptable levels, and they must be durable to avoid frequent need for replacement. The materials must also be able to absorb the energy from multiple impact events imparted by occupants.
In recent years, the armor level of tactical vehicle body panels has increased significantly, and this increase has been achieved using material which is increasingly stiff. However, rigid material can cause increased injury to soldiers during a collision, a flexible and compressible impact energy absorbing material is more desirable.